Introducing the unichron gem

require 'unichron'

r = Unichron.new('next tuesday').to_time
#=> 2020-11-10 12:00:00 +0000 
r = Unichron.new('last sunday in October at 2am').to_time
#=> 2021-10-31 02:00:00 +0000 
r = Unichron.new('5 minutes').to_seconds
#=> 300